Irrigation management system

ABSTRACT

An irrigation management system monitors irrigation parameters, including progress of flood irrigation water admitted onto a farm field, water levels in ditches, basins or boxes, soil moisture, water usage and other important factors. In flood irrigation a series of small, inexpensive sensors detect the presence in each of the sensor locations in a field, and each sends a signal when water first reaches the sensor. In a preferred form the sensor communicates by long-range radio communication either directly with a hub or gateway, or by sending a transmission that is relayed from location to location and ultimately to the hub or gateway. All aspects of irrigation water need, availability, task completion, pipe and equipment status, and water usage are monitored and communicated to the farmer. The system allows efficient water management and reliable and responsible irrigation at all irrigated fields.

This application is a continuation-in-part of application Ser. No.16/043,891, filed Jul. 24, 2018, now U.S. Pat. No. 10,524,430, issuedJan. 7, 2020, which claimed benefit of provisional application No.62/650,166, filed Mar. 29, 2018.

BACKGROUND OF THE INVENTION

This invention concerns irrigation water management, on farms and inirrigation districts, especially including flood irrigation, and alsoconcerns groundwater replenishment.

Irrigation of a farm field by flood irrigation, typically on arelatively flat field with a slight downward grade, is common in somegeographical areas. For example, many crops are irrigated by floodirrigation in the Central Valley of California. In most recent years,water has been in short supply.

For such irrigation, water stored behind dams and directed throughirrigation channels or pipes is applied by releasing the water at thehigher end of a field and allowing that water to flow by gravity overall areas of the field. The field may be as small as about one-half acreor it could be many acres. Typically the field will have one crop, thewater needs of which should be consistent in all areas. However,variations occur in surface contour, soil type and subsurface geologyand, for example, some areas will drain water more quickly, with othersholding water longer on the surface.

An objective of the invention is to maximize efficiency of water use inmanagement of flood irrigation and other forms of irrigation on farms.In flood irrigation this involves sensing the presence of surface waterat a series of different positions in a field, letting the farmer knowwhen water reaches a particular area of the field and, optionally, howlong the water remains. Also, related objectives are to measure soilmoisture at various points and to determine water surface levels,including upstream and downstream of a gate, all to provide the farmerwith complete and thorough information regarding an irrigation system toenable the farmer to manage irrigation more precisely and efficiently,saving water and time.

A further objective of the invention is irrigation water management andmonitoring in irrigation districts, including use of surface water andgroundwater, and the replenishment of groundwater.

The following patents and applications may have some relevance to theinvention: U.S. Pub. Nos. 2017/0127622, 2016/0219805, 2016/0183484,2014/0361887, 2014/0225747; U.S. Pat. Nos. 8,739,830, 8,643,495,8,326,440; China Pub. Nos. CN 105123446, CN 104542197 and CN 103210819.

SUMMARY OF THE INVENTION

Pursuant to one aspect of the invention an irrigation management systemmonitors progress of flood irrigation water admitted onto a farm field.A series of small, inexpensive sensors detect the presence in each ofthe sensor locations in the field, and each sends a signal when waterfirst reaches the sensor. In a preferred form the sensor communicates bylong-range WiFi (LORA) or similar long-range wireless communication,either directly with a hub or gateway, or by sending a transmission tobe relayed from sensor location to sensor location and ultimately to thehub or gateway. In that form each sensor can receive signals as well assend signals. The system allows efficient water management and reliableirrigation at all areas of an irrigated field. An important feature ofthe invention is construction of the sensor device. The sensor in oneimplementation is formed of inexpensive plastic plumbing pipe, such asPVC pipe, with an internal diameter of at least two inches, or a rangeof about two to four inches. The bottom end of the pipe section is fullyclosed, either with an integral closure or a cap, and the housing has atop cap which is removable. When the top cap is installed the sensorunit is fully sealed against intrusion of moisture. The top cap may bethreaded, or simply fitted closely onto the top end of the section ofplumbing pipe. The housing could be formed of other materials, such ascustom injection-molded components if desired.

Near the bottom of the sensor device, approximately one-half inch to oneinch above the bottom end, are a pair of conductor probes isolated fromeach other and extending from the interior to the exterior of thehousing, positioned to sense surrounding water that reaches apreselected depth threshold (such as one-half inch to one inch). Notethat only one sensor need be at the desired sensing level, the otherbeing lower and optionally integral with a spike extending downward fromthe housing to hold the unit at the selected location on the ground.

Within the interior of the housing is a battery, an antenna, amicroprocessor and a radio transmitter (LORA or other long-distancewireless), as well as a circuit connected to the two external conductorprobes for detecting the presence of surrounding water. The sensorcircuit includes the battery and an activator (which may be themicroprocessor) such that in absence of surrounding water an electricalpotential exists between the external conductor probes, without currentflow, but in the presence of surrounding water the circuit is closed,causing the processor to fully awaken and to send a wireless signalindicating the presence of water.

These small, compact sensors are placed at a series of locations on afield to be subjected to flood irrigation. They enable the farmer tomonitor, with resolution as desired, effected by the number and densityof sensors in the field, the irrigation water reaching each of manydifferent areas of the field. When irrigation water is admitted from thehigh end of the field to flood the field, the water sensors atrespective positions in the field will send a signal upon water reachingthe preselected depth surrounding the respective water sensor, therebyproviding information as to progress of irrigation water in reachingdifferent areas of the field.

In one implementation of the invention, the sensors, or at least some ofthem, can receive and transmit, and a signal from one sensor can bepassed on in chain-like fashion successively to and from further sensorsuntil the signal reaches the hub or gateway. This enables the signal totravel as far as desired, as long as the chain segments are functional,which will require each of the sensors in a communication path be“awake” to the extent of receiving a signal. This could be only selectedones of the sensors sufficient to establish a live path.

Alternatively, all sensors could remain quiescent until water awakensthem, and hubs could be placed as needed to enable the communicationpath. In an alternative implementation each sensor is capable of sendinga signal that will reach the hub or gateway directly, not involvingintermediary sensors.

Each sensor can include a GPS transmitter if desired, for reporting itsposition with a transmitted signal. This will increase a sensor's awaketime slightly, as the sensor acquires its GPS position, then the sensorwill go back to sleep. The use of GPS enables a map to be presented onthe farmer's screen (whether a PC or a mobile device), showing anaccurate location of each sensor on the field. With the sensors beingsmall, the GPS locator feature can be important in finding a sensor. Asan alternative, however, the sensors can be noted as to position whenplaced (such as using a separate hand-held GPS device, such as on asmartphone), which will also enable a map to be created. Each signalfrom a sensor is unique and identifies the particular sensor.

Further, a solar cell can be provided on or near each sensor, to chargea rechargeable battery in the unit.

In one embodiment the gateway can send a confirming signal back to asensor, indicating the sensor's transmission has been received. In thiscase all sensors are receivers as well as transmitters.

The microprocessor used in the unit can be a Particle Photon Wi-Ficonnected microcontroller, although other processors can be used.

The invention further encompasses aspects of irrigation water monitoringand management for a farm or group of farms or other irrigated land areasuch as in an irrigation water district. Where groundwater is used as aprimary or secondary source of irrigation, groundwater depletion is aconcern, and the invention encompasses a system for monitoringapproximately an amount of groundwater replenishment occurring on farmfields due to irrigation, and also replenishment of groundwater viagroundwater replenishment basins. Further, the invention encompassesmonitoring, from a central location, level of water in a series ofirrigation water delivery pipes, canals or ditches that conveyirrigation water to a series of farms in irrigation districts or otherirrigation water distributing organization. Monitoring can be viawireless data transmission from depth sensors and flow meters. Wheregroundwater is used, the invention provides an approximation ofreplenished groundwater from irrigation, especially flood irrigation,which can be balanced against water usage on a farm or group of farms.

It is accordingly among the objects of the invention to provide a simpleand conveniently used farm management system, particularly to monitormany different points in fields with regard to flood irrigation andwater status, for providing comprehensive data to the farmer, increasingthe farmer's efficiency and precision in managing irrigation andresulting in much more efficient use of time and of water and assurancethat crops are receiving the correct amount of water. Another object ismonitoring irrigation water status, levels and use from a centrallocation, such as in an irrigation district, which can be along withelectronic monitoring of groundwater replenishment via irrigated fieldsor groundwater replenishment basins. These and other objects, advantagesand features of the invention will be apparent from the followingdescription of a preferred embodiment, considered along with theaccompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an aerial plan view of a farm exemplifying the system of theinvention.

FIG. 2 is a perspective view of a water presence sensor as a keycomponent of the system of the invention.

FIG. 3 is a perspective view of the sensor with cap removed, showingcomponents contained inside the waterproof capsule.

FIG. 4 is a schematic drawing indicating concepts of the invention.

FIG. 5 is a drawing indicating schematically a farm field andprogression of flood irrigation across the field.

FIG. 6 is a flow chart indicating functions of the system.

FIG. 7 is a schematic circuit diagram for the sensor.

FIG. 8 is a plan view showing a printed circuit board according to oneimplementation of the invention.

FIG. 8A is a perspective view of a differential water level sensor inone embodiment of the invention.

FIG. 9 is a schematic elevation view indicating another embodiment of asensor of the invention.

FIG. 10 is a block diagram showing inputs on a farm to a central hub orgateway and use of data from the inputs.

FIG. 11 is a flow chart outlining procedure on a farm for irrigating byflood and by micro irrigation.

FIG. 12 is a pictorial view in perspective showing a surface watersource such as an irrigation canal, with a series of lateral canals orditches serving farms or groups of farms for irrigation.

FIG. 13 is a schematic view indicating an example of an irrigation waterdistrict or system that delivers surface irrigation water to a pluralityof distribution points, from which water is delivered to farms or groupsof farms via canals, ditches or pipes, and indicating monitoringaccording to the invention.

FIG. 14 is a schematic view in sectional elevation, illustratingequipment and a method for monitoring seepage of irrigation waterdownward through soil, below the level of plant roots, potentiallyreplenishing groundwater, utilizing a series of moisture sensors atdifferent levels.

DESCRIPTION OF PREFERRED EMBODIMENTS

The system of the invention in one aspect is an open platform hub andspoke, or combination mesh and hub/spoke, connected farm utilizing longrange Wi-Fi radio technology. As explained above, the system includesspecial sensors and transmits information to a central hub, or gateway,the farm having many of these sensors in different fields. The systemprovides comprehensive irrigation water status information, includingreal-time data, enabling the farmer efficiently to manage the use offlood irrigation water and to detect problems involving brokenpipelines, overflows or accidently flooded areas. The presence of waterat any of the many sensors can be sent to the farmer or manager via textmessage or other forms of communication in a portable smartphone orother device, including urgent alerts in the event water is detectedwhere it should not be present. The system allows the farmer to preventover watering, as well. Water costs can be greatly reduced, as well aslabor costs.

In an embodiment of the system level sensors are also employed,providing the farmer data on levels at strategic locations such as atbasins or channels upstream and downstream of valves, for water flow andavailability status. Further, soil moisture sensors can be included insome fields.

The system of the invention can monitor other aspects of the farm, suchas the use of equipment, and the location and movement of equipment.

FIG. 1 shows an example of a farm 10, in aerial view, using the systemof the invention. The farm has various fields typically with differentcrops, the fields indicated as 12, 14, 16, 18, etc. Barns, sheds andstorage for equipment, grain, etc. are indicated within rectangularareas at 44 and 46. A farmhouse and associated buildings are shown at50. A gateway for the system can be located in the farmhouse, in otherbuildings that might be located in the areas 44 or 46, or in anysheltered housing at a convenient, accessible location.

FIG. 1 also shows, as an example, locations of various sensors on thefarm, sensors that can transmit data signals to the hub or gateway ofthe system. A series of eleven sensors 52 are shown in the field 30, atpositions determined to be critical indicators of the progression anddistribution of flood irrigation across the field, the field typicallyhaving a slight downward grade from the flooded end to the lower end.The field 18 is shown with a series of sensors 52 at selected locationsin the field, and similar sensors 52 are shown in several other fields.These are water presence sensors, although they could have otherfeatures as well, as discussed below. In the field 30 the sensors areshown in a view that might be presented on a screen of a computer orportable device. Five of the sensors 52 near the higher end of the fieldhave blue indicators, to show water sensed at those locations. The othersensors in the field are shown dry.

Other sensors are shown at 55, arranged along an irrigation ditch orpipeline. These sensors will report water level, which also provides aninference of the level of pressure being exerted on a pipeline. In somecases a pipeline can only withstand a predetermined pressure, and thesystem can provide alarms if that pressure is being approached, orexceeded. This can be an urgent situation and can be addressed by thefarmer to avoid a pipe or ditch failure.

In FIG. 1 a field 24, typically an orchard, has been sprayed, so thatentry by farm personnel should be prohibited for a prescribed period, asindicated in the drawing. This can be initiated using a sensor on thetractor used in the spraying, including an input of the duration of timefor the prescribed period.

An embodiment of the water presence sensor 52 is shown in FIGS. 2 and 3,with an example of one form of preferred circuitry shown in FIG. 7. FIG.2 shows the sensor device 52, as one example, formed in a simple andrelatively low cost construction using PVC pipe components 56 and 58.The cap 58 can be connected to the base 56 by screw threads, or simplyby a close fit, with the two components tightly held together inwaterproof relationship. The sensor device has a pair of contacts forsensing the presence of water, and these can be a bottom prong 58 thatanchors the device in the ground, as one contact, and a second contact60 at a selected height for activating the electronics of the devicewhen water reaches the level of that contact 60. An antenna 62 canextend out the top of the cap, or an internal antenna can be used. Thecontacts and antenna are sealed to the housing so as not to allowintrusion of water. Instead of the PVC components, the sensor casing canbe an off-the-shelf plastic electronics box with openable, sealed cover.Many such boxes are available.

In FIG. 3 the cap 58 has been removed, revealing electronic componentsin this preferred embodiment, contained within the sealed interior.These include a battery 64, which can use lithium and be rechargeable(or other types of battery, such as four AA cells, non-rechargeable). Acharge controller PCB is shown at 66 in this embodiment (TP4056-Protectshown here), and at 67 is the LORA radio PCB. FIG. 8, discussed below,shows a main PC board for one implementation of the invention. Oneexample of a processor for the system is a Particle Photon Wi-Ficonnected microcontroller, capable of LORA transmission.

The diagram of FIG. 4 indicates general layout of the system and variousfunctions. The hub or gateway of the system is indicated at 70,preferably located centrally on the farm to receive wireless signalsfrom a variety of sensors on the farm. As indicated, the hub receivesdata and loads the data to a cloud based server via cellular signal orvia an available local Wi-Fi system to the Internet. The data can thenbe retrieved by the farmer or farm manager from any location, and alertsor alarms can be delivered to the farmer if something urgently needsattention.

FIG. 4 also indicates signals going to and from the hub 70, the hubcommunicating with various sensors. Water presence sensors are noted at52, but also indicated are water surface level sensors 55, discussedabove in connection with FIG. 1, for monitoring water in a pipeline orin a canal or basin or irrigation ditch delivering water. Further, thehub 70 can be connected, preferably with two way communication, to valvesensors 72 to report the status of valves, and pump power usageindicators 74. Further, GNSS (global navigation satellite system)devices can be installed on farm equipment and various other assets ofthe farm where tracking would be useful, as indicated at 76. Forexample, tractors can each be equipped with GNSS, as can implementstowed by tractors, and various other mobile assets of the farm.

FIG. 5 schematically illustrates a farm field 80, which trends downhillin the direction of the arrow 82. Irrigation water is released at thetop end 83 of the field, as indicated. The water progresses along anadvancing front indicated at 84. Water presence sensors 52 to which thewater has advanced are shown shaded in the drawing, and these have senta signal to the hub of the system, since the two exterior contacts oneach of these sensors have closed the circuit and activated theelectronics. Additional sensors 52 a in FIG. 5 have not yet beenactivated. This will show any irregularities or anomalies in the patternof water advancement, i.e. in watering the crops in the field. The datacan be presented pictorially on a computer screen or the screen of asmartphone or other portable device for observation by the farmer. Theremay be sensors that have not been activated, thus areas not reached bywater, or there may be some that require longer than expected to beactivated. This can indicate the need for some adjustments to thesurface grade.

FIG. 6 is a simplified flow chart illustrating operation of the systemof the invention in the block 90. The more densely the sensors areplaced, the higher the resolution provided to the farmer as to wettingdata as the flood irrigation is advanced on the field. After initialtesting and calibration, the block 92 shows that all electronics of thesensors are quiescent, drawing almost no power at this point (preferablyless than 20 milli Amps). An electrical potential exists between the twoexterior contact probes, but without current flow. Flood irrigationbegins as indicated at 94. The irrigation water advances down the field,such that water rises and contacts the sensor probes of the sensors, oneby one. This is effective to close the sensor circuit of each sensorwhich has been reached by the water, as indicated in the block 96. Thistriggers flow of current, at a voltage of greater than a threshold of0.5V.

As in the block 98, with the circuit closed and voltage exceeding 0.5V,this wakes up the microprocessor. The microprocessor causes a signal tobe transmitted (e.g. a LORA signal), indicating “water present”. Thissignal goes to the gateway or hub 70. It may not be sent directly to thehub; in an embodiment of the invention it can be sent successively fromsensor to sensor to reach the gateway 70, provided the sensors are bothreceivers and transmitters.

In a preferred implementation of the system, receipt of the signal atthe hub 70 must be confirmed or the signal will be retransmitted by themicroprocessor in the sensor. See the decision block 100.

As in the block 102, after the signal has been transmitted and received,all electronics return to the quiescent state, except that a smallcurrent continues in the sensor circuit. The voltage over the thresholdof 0.5V will exist, but with a very small flow of current and low powerdraw, as long as water remains. No further signal will be transmitted.

After the water recedes below the point at which the sensor's contactsare wetted, the sensor's circuit opens, as in the block 104. In one formof the system the electronics of the sensor are all reset at this point,returning status of the sensor to the block 92 as indicated the dashedline 106. However, in another implementation indicated in the optionalblock 108, the opening of the sensor circuit will be an event thatcauses the microprocessor to transmit a second signal, different fromthe first signal, and confirming that the water has receded. This willgive the farmer additional data indicating the length of time duringwhich the water was present. Again, as noted in the decision block 110,the system can require confirmation that the signal was received. Oncethat has occurred, the status of the sensor returns to block 92.

FIG. 7 shows a preferred embodiment of the electronics contained in asensor 52. The sensor's probes are indicated by lines 58 and 60 in thediagram, which can be connected by water as noted at 112. Themicroprocessor, which can be a Particle Photon Wi-Fi connectedmicrocontroller, is denoted at 68. A LORA transmitter of the sensor isshown at 67. A GPS can be included in the sensor, as discussed above,and this is indicated in the diagram at 114. The battery 64 is alsoshown, indicated as a rechargeable battery which in a preferredembodiment is charged inductively; FIG. 7 indicates an inductivecharging coil 116 in the sensor in a position to be charged from outsidethe housing, this coil 116 being connected to a battery chargecontroller 66. Other batteries can be used, such as AA non-rechargeablecells. Any source of approximately 5V is adequate.

As indicated in the schematic, the closing of the circuit via theconductor probes 58 and 60 causes a flow of current at 3.3 volts in themicroprocessor 68, and the microprocessor activates the LORA transmitter67, again with current flowing at a voltage of 3.3 volts thetransmitter. Further, the microprocessor controls the GPS 114,activating the GPS to send a signal only when controlled by themicroprocessor to do so. Again, current is shown flowing at 3.3V. TheGPS receives satellite position data and transmits that data to themicroprocessor, as indicated in the drawing.

The components of the sensor for one embodiment of the invention arealso shown in FIG. 8, in this case a water depth sensor. FIG. 8 shows aprinted circuit board 120, in this case connected to an ultrasoundsurface distance sensing unit 122. This includes an ultrasoundtransmitter 122 a and receiver 122 b, for determination of distance fromthe sensor to a surface, e.g. a water surface. Otherwise, the PC board120 has most of the components shown in FIG. 7 (without GPS). The LORAradio transmitter is shown at 67, the microprocessor is at 68 and thecharge controller is shown at 66. The device shown at 124 in FIG. 8 is a3.5V to 5V converter, which is needed for the ultrasound surfacedistance measuring device 122. These electronics can be the internalcomponents of the depth sensors 55 discussed above.

FIG. 8A shows an implementation of a dual depth sensor 55 a with theelectronics described above for sensing depth by distance to the watersurface. The two-sensor device is used for differential depths, such asin a box, at upstream and downstream sides of a gate valve, to provideimportant information to the farmer. One main PC board (120, above) canserve both ultrasound units, with only the specific ultrasoundelectronics duplicated. The embodiment shown has a housing of PVCcomponents, and is connected to a solar array 123 for recharging thebattery of the device during the day.

FIG. 9 shows schematically another form of sensor 125 that can beincluded with the system of the invention. The sensor can have a baseand cap 56 and 58 similar to the sensor 52 described above, but with ataller profile, an additional section of the sensor being shown at 126.Here, the sensor 125 can sense a successive series of water levels, toindicate depth or pressure. Thus, contacts are shown at 128 a, 128 b,128 c, 128 d and 128 e. The signal sent by the microprocessor in thiscase will indicate the level reached by the water. Further, the sensor125 can include sensing of soil moisture capacity. Three fork-shapedprobes 130 are indicated as connected to the device 125, each toindicate the capacity of the soil-held moisture at a different level. Apotentiometer signal is received and fed to the microprocessor toprovide moisture at each depth, with this data then sent to the hub orgateway.

An important aspect of the invention is that the water presence sensoras described above constitute the basic sensor architecture for allsensor devices in the system. All the basic components are the same forwater presence sensors, water level sensors, soil moisture sensors andintermediate hubs. These basic components are the microprocessor, theLORA communication device, PC board, antenna and battery (which may berechargeable, with charging circuitry, or can be recharged with a solarPV array nearby). GPS may be included in all. Each type of specificpurpose sensor has its own additional component(s), as for moisturesensing, level sensing, etc. Some of the devices, as noted above, canhave off-the-shelf electronics boxes as housings. In particular thegateway or hub 70, moisture sensors and water level sensors can be insuch housings, as can be the water presence sensors.

One embodiment of a preferred farm system of the invention includes thewater presence sensors 52, water level sensors 55 (using the ultrasounddistance measurement device 122), soil moisture measurement devices, agateway to receive transmissions from the various sensors, and,optionally, intermediary hubs as needed to relay signals from thesensors to reach the gateway, in the event sensor to sensor relayed“mesh” communication is not used. The farmer is thus provided withcomprehensive data concerning irrigation conditions on the farm, as wellas water available at any given time, and rate of water use. Thisinformation is available in real time, with alerts to the farmer in theevent of urgent situations. Alerts can be via a mobile device such as asmartphone, or received via wireless signal or local Wi-Fi, from theInternet. The Internet need not necessarily be involved; the data couldbe communicated from a local server computer to the farmer's smartphonedirectly, via long-range Wi-Fi existing at the farm. However, acloud-based server has several advantages and is preferred. Programmingon the server can serve many farms, and is fairly sophisticated, withthe ability to receive and manipulate many types of data and to presentrelevant status and maps as well as to retain historical data for thefarmer, recallable when needed. Also, the cloud-based server enables thefarmer to monitor conditions when away from the farm.

In the diagram of FIG. 10 the system of the invention is schematicallyillustrated. This diagram essentially expands on the simplified diagramof FIG. 4. The central hub or gateway is shown at 70, receiving datafrom a multitude of sources, all over local Wi-Fi, preferably long rangeWi-Fi or LORA. Examples of data inputs are shown in the schematic. One(of several, or many) flood-irrigated field is shown at 30, with aseries of the water presence sensors 52 positioned in the field.Wireless transmissions from these sensors to the gateway 70 areindicated. Optional “mesh” communication, from sensor 52 to sensor 52and ultimately to the gateway, is indicated at 132. This has powerdrawbacks and more preferably intermediate hubs 134 can be positioned atstrategic locations to carry the signals from the sensors 52 ultimatelyto the gateway 70, thus requiring lesser reach for the Wi-Ficommunication. Each sensor 52 directly communicates to a hub 134,allowing the sensor 52 to power down, returning it to “sleep” mode andconserving battery. Hubs 134 will always be powered up, with batteriespreferably charged by adjacent solar panels, so that battery usage atthe hubs 134 is not an issue.

Water level sensors at indicated at 55 (with ultrasonic distance sensors122), providing water level data for ditches, basins and boxes, and alsodifferential levels where needed. As noted, solar panels 123 preferablyare used to charge the batteries of the level sensors 55 so they canremain powered. This can also be the case with the soil moisture sensors125. Pump status data is shown as sent to the gateway 70, as indicatedat 136. Soil moisture sensors are indicated in the box 125, sendingtheir signals when required to provide soil moisture content data. Thesesensors, shown in FIG. 9, can be similar to the soil presence sensors52, with the same basic electronics by including the moisture sensingapparatus, such as illustrated in FIG. 9. Water level sensors and soilmoisture sensors are best served by adjacent solar panels to rechargetheir batteries during the day. The box water level sensors preferablyare always operational, not going into sleep mode. The same ispreferably true of soil moisture sensors. In fact, these solar-rechargedsensors can act as some or all of the intermediate hubs 134, if instrategic locations for the needed retransmissions.

Further, FIG. 10 shows a tractor 138, towing a farm implement 140, as anexample of farm equipment that can be monitored as to position and use,each sending Wi-Fi signals (LORA) to the gateway 70 as requested. Asdiscussed above, any number of farm implements and equipment can bemonitored, each having GPS as noted at 142 in the drawing. The systemcan thereby provide data as to real-time position and movement oftractors and farm implements, and can maintain a historical database asto how much use each farm implement, particularly tractors, has had overa requested period of time, and what implements were towed by thetractor. With this information the farmer can appropriately rotate farmequipment to get maximum usage and life.

Also in the diagram of FIG. 10, the Internet with cloud server isdenoted at 144; communication from and to the gateway 70 can be vialocal Wi-Fi or cellular communication. As illustrated, the server canprovide information to the farmer via the smartphone 146 and/or via aportable or desktop computer of the farmer. As noted, these data can bereal-time status data and/or historical data, regarding water presence,pumps, moisture, levels, differential water levels and GPS position ofsensors and of farm implements, as discussed above.

The flow chart of FIG. 11 outlines the steps taken by a farmer in atypical crop watering scenario. The block 150 indicates opening thesoftware of the system, which can be initiated by the farmer using acomputer or a smartphone. This user interface connects to the database,preferably a cloud server. In this case the farmer checks soil moisture,indicated by the block 152, which can be by using electronic soilmoisture monitors including the moisture probe features 130 as indicatedin FIG. 9. The soil moisture is preferably reported at different depths,important for many crops depending on typical root penetration of thecrop. For other fields without soil moisture probes, the farmer simplychecks the fields by direct observation, and/or weather over theprevious days or weeks and predicted weather, duration of time since thelast watering, the nature of the soil in the field, recent temperaturesand humidity, sun exposure and other relevant factors. The decision asto whether to irrigate is noted at 154. If the decision is negative, thefarmer can examine historical data as to trends and differences inwatering cycles, for help in making irrigation decisions going forward.This is noted at 156. The decision might be to wait one more day, asnoted at 158 and 160, and if the decision is not to wait another day(based on the trends and differences observed), the flow goes to thedecision block 162, where irrigation method is selected. For microirrigation (block 164), as in spraying with sprinklers or dripirrigation, driven by a pump, the farmer selects the water source orsources to be used (166). In a system of irrigation pipes or ditches asthe supply of water, the farmer may need to contact the irrigationdistrict as to the availability of water, and request a desired flowrate or quantity of water. If sufficient water is not available,available well water can be used alone or in combination with districtwater.

The block 168, “begin flow”, indicates the beginning of water delivery.In an irrigation district the source could be one or several miles away,upstream of the farm. A gate will be opened, typically by an irrigationdistrict person. Depending on the distance of the gate from the farm, itmight require several hours before the water arrives at the farm.Because the time of water arrival is not precisely known, the farmermonitors a box level, as noted in the block 170, to determine when thewater is available at the farm. This can be done with an automatic alertto the farmer on a smartphone, from a signal sent by a device such asshown in FIG. 8, a distance sensor that will provide the farmer withwater level in the box or in an irrigation canal or ditch. When thewater rises in the box, and reaches the desired range as needed for theirrigation (decision block 172), the irrigation is started, as noted inthe block 174. If the level of the water supply has not reached thedesired range, the farmer can be alerted of this condition, as in theblock 176, or he can simply be notified only when the water does reachthe desired range.

Irrigation is commenced, and this is micro irrigation involving pumps,so the block 178 denotes that the farmer checks pressure in pipes. Thiscan involve several check points and is provided so the farmer canassure that pressure is within the desired and safe range, as noted inthe decision block 180. For example, if irrigation water is being pumpedout at too great a flow rate, faster than the water is being deliveredto the box, this will cause a problem and can be indicated by pressureor water level upstream of the pump. If pressures are too high in pipesdownstream of the pump, this can indicate a blockage or partialblockage, at a filtration point or at some of the irrigating nozzles.Any blockages or high resistance downstream of the pump can present adanger of burst pipes and must be addressed by the farmer.

The block 182 notes that the farmer is alerted to any out-of-rangepressures. If pressures are within range, this is indicated to thefarmer (block 184), and at this point the farmer can be prompted toindicate a duration for this irrigation cycle, block 186.

Irrigation continues for the selected duration (block 188), and, whenthe duration has expired (block 190), the water flow is stopped at thesource (192), i.e. the source of the pipe or ditch irrigation waterwhich might be upstream several miles. Again, pressure and levelspreferably are monitored, as noted in the blocks 194 and 196, to be surethe system shuts down properly. In the gravity system of deliveringirrigation water to a number of farms, as is the case here, water comingdown the ditch or pipe to the farm must be used, and thus irrigationcontinues until levels and pressures are safe and within ranges, as inthe decision block 198. When this point is reached, irrigation isterminated (200), and a report (202) is sent to the farmer (received ona smartphone or computer), reporting the duration of the irrigation,approximate number of acre feet used, and how many flushes haveoccurred.

Backflushing is required for filters used to remove particulates fromwater to be used in irrigation. These includes sand filters and othertypes of filters, subject to clogging if not periodically backflushed.Different water sources have different filtration needs and are animportant factor in determining how often the system will need to flushfilters. Well water typically is cleaner than canal or ditch water. Thesystem of the invention preferably operates backflushing not based ontime intervals, which can waste a considerable amount of water bybackflushing when not needed. The system described herein does notinitiate flushing based on time, but rather on differential pressuresand also based on the water source; well water will need very littlefilter flushing. By monitoring differential pressures upstream anddownstream of the filter, the purer nature of well water isautomatically accounted for.

Going back to the block 162, when the irrigation method is floodirrigation (block 202), again the water source to be used is selected,as noted at 204, and flow begins (206), which again may be from a sourcefar upstream, requiring the opening of a gate. The farmer checks the boxlevel (208), and steps 210, 212, 214 are similar to those described withrespect to the blocks 172, 174 and 176. Here, flood irrigation iscarried out by gravity flow, so the farmer checks the water flow, atblock 216. The farmer needs verification that water level in the box,once present, is at a high enough level but not too high. Differentiallevel sensors, as discussed above, can be used to provide moreinformation, not only as to level but rate of flow, as by monitoringlevel both upstream and downstream of the farmer's gate, in a box.

If the flow is outside of an acceptable range (decision block 218), thefarmer is alerted (220), as on a computer or a smartphone. Once the flowis within limits, the progress of the flood irrigation in one or morefields is monitored, see block 222. For this function the water presencesensors 52 described above can advantageously be used. If desired, thefarmer can be presented, on a computer or smartphone, with a real-timemap showing which sensors in a field are wet and which remain dry. Asdiscussed earlier, there can be many sensors in a field, for higherresolution of data to the farmer.

At the decision block 224 the query is whether irrigation of the fieldis complete, but this is actually a projection as to whether it appearsto be complete at this point. If not, and progress is not within range(decision block 226), the farmer is notified (228). If irrigation of afield is taking too long, the farmer will want to inspect to determinewhat has gone wrong. If the irrigation is within range (but not yetfully complete), again progress is monitored, and when the irrigationappears to be essentially complete the water is shut off at the source(unless another field is to be irrigated); see block 229. If the watersource is distant as discussed above, water will continue to bedelivered for a time. If the source is local, such as from ground water,then no projections need be made and the water source can simply beswitched to another field or different portion of a field, for example.

The block 230 denotes that, in the case of a distant water source, theprogress of the irrigation continues to be monitored, to be sureirrigation of the field is completed. If the irrigation data is notwithin range (232), again the farmer is alerted (234). If the irrigationis complete and within range, it is terminated, as at 236. Again, areport is sent to the farmer (238) providing all data on irrigationduration, the quantity of water used and any irregularites.

As noted above, the invention also encompasses monitoring water usebeyond a single farm, including status of water in pipes, canals orditches, volumetric flow rate of water through such water deliveryconduits, and also monitoring indications of groundwater replenishmentin a region where groundwater depletion is a concern. Some or all of thefarms may employ surface water for flood irrigation and/or groundwaterfor micro irrigation. In addition, groundwater replenishment can beestimated via soil moisture content, especially where flood irrigationis used but also where micro irrigation is used. All monitoring can bevia electronic devices on the farms and along water delivery canals,ditches or pipes, with wireless data transmission capability so as toenable monitoring at a central location.

FIG. 12 schematically illustrates, in a generalized pictorial view, apart of an irrigation system in which a river or canal or other surfacewater source 250 provides water to a plurality of water users located inthe vicinity of the water source 250. This could be primarily irrigationwater serving a number of farms, as indicated in the drawing, and it canalso include industry, such as indicated at 252. The pictorial diagramindicates a reservoir at 254, which could be the source of the water inthe canal 250.

The view of FIG. 12 indicates use of water level sensors, as well asweirs and gates that control flow of water, and flow measurementdevices. All level and flow measurement devices are preferably wirelesscommunication enabled, so that conditions can be monitored from acentral location. The weir shown at 256 in the river or canal 250 isused to regulate downstream flow. Water surface level can be reported atseveral locations noted at 258 along the waterway 250, both above andbelow the weir. As discussed above, these water level detectors cancomprise ultrasonic level sensors, each of which preferably beingequipped with wireless data transmission capability.

Water is distributed via various canals, ditches or pipes, as shown at260. For this purpose a lateral distribution gate 262 is positionedwhere water is released from the canal 250 to the lateral canal or ditch260. Downstream gates are provided from the canal or ditch 260, such asat 264, for admitting water to individual farms or fields via a lateralditch or pipe 266. If desired the position of the gates such as at 264can be monitored via an electronic indicator at the gate, with wirelessdata transmission capability.

As water flows through the main river or canal 250, water level sensors258 report to the central location surface levels at specific locations.Those locations can be given thresholds, and when water level is outsidethose thresholds alerts can be activated. This helps provide moreaccurate water distribution as well as advance warning of potentialdanger in the system, to prevent damage to the canals, ditches or pipesthat deliver water as well as surrounding areas and facilities. Atvarious locations, such as at the weir 256 and at gates 262 and 264,volumetric flow measuring devices can be installed to provide accuratedata on flows of water in the system, for purposes of allocation,billing and also safety.

FIG. 13 provides a schematic showing important aspects of the system ofthe invention. Again, a river or canal (or possibly a reservoir) isshown at 250. One primary lateral canal shown at 260 delivers water to adistribution location 270, which can be an irrigation district as notedin the drawing, which might serve thousands or tens of thousands ofacres. For purposes of illustration this distribution site 270 can beconsidered a central location or headquarters that receives wirelessdata from a large number of sources indicating water status, waterusage, gate or valve positions and in some cases, groundwaterreplenishment.

The drawing indicates a large number of irrigation water deliverylaterals 272 which can be canals, ditches or pipes or combinationsthereof, emanating from the distribution facility 270.

One farm in this acreage is indicated at 274, receiving water from abranch ditch, canal or pipe 272. Water level sensors 258 and/orvolumetric flow measuring devices 276 can be located at desiredpositions along the ditch or pipe. Where the water reaches the farm aninflow box or basin 278 can be provided, preferably with a gate, andincluding an electronic water level monitor 258.

As noted, the farm 274 is an example of a farm that applies floodirrigation to at least some of the fields, received via the ditch orpipe 272, and also utilizes groundwater, which may be as a backup or aprimary source of irrigation water, as in micro irrigation. The farm canbe similar to the farm outlined in the embodiments described earlier. Onthe farm one or more boxes or basins 280 are downstream of the inletbasin 278, and each can be fitted with a water level sensor 258. Asexplained in the embodiments described above, these level sensors, eachequipped with wireless data transmission electronics, enable efficientwater management on the farm. The wireless transmission capability atthe sensors is preferably at least one quarter mile.

Another feature of the invention, as noted above, is the monitoring ofwater seepage down through the soil, particularly on a farm such as at274, as an indicator of replenishing groundwater supply. At strategiclocations on the farm, subsurface moisture sensors, generally indicatedat 282, are placed for this purpose. One of the subsurface moisturesensors is shown at a dedicated groundwater replenishment basin 284 thatcan be located on the farm. Such a replenishment basin 284, several ormany of which can be located in the irrigation district, on farms orother locations, can receive not only rainwater but also deliberateflows of water from the distribution source 270 via the pipe or ditch272, for recharge of groundwater in a season when water is relativelyabundant, thus deliberately using this water to replenish groundwaterrather than allowing the water to run off via surface drainageultimately to streams or rivers. Groundwater is a critical issue in mostirrigated parts of the U.S., and its use and replenishment arecontrolled by law in some jurisdictions. As described above, each ofthese monitoring devices 282, 258 and 276 can be provided with wirelesselectronic data transmission, to be received at a central location suchas the facility 270, or any other monitoring station in the vicinity.Wireless transmission can be indirect, first received at one or aplurality of wireless data hubs 286 as shown in FIG. 13, with the datasignals to be re-transmitted from the wireless hub 286 to the centrallocation, which can be the facility 270.

FIG. 14 shows the soil moisture content monitoring, for the purpose ofdetermining groundwater replenishment, in greater detail. In thisschematic cross section view, plants, e.g. crops, are shown at 288,planted in the soil 290 of a field, e.g. a farm field. Above groundwater detection is shown at 292, using one or more water presencedetectors 52 described above, here shown sensing at three differentlevels above the surface of the field, so as to indicate depth. Thethree detection points can be in a single housing unit 125 such as shownin FIG. 9, with a series of water depth points. FIG. 14 also showssubsurface moisture detection at a series of different depth points 294,296, 298 and 300. These also can be part of the same device 125 of FIG.9, with electronics for both water presence/water depth detection andmoisture detection at multiple levels, all such electronics beingcontained in the housing 125. In addition, the housing includes wirelesstransmission electronics, as explained above, for providing data signalsto be transmitted over a long distance (with or without intermediatehubs for re-transmitting signals) to a central monitoring location. Asan alternative, the moisture detectors could be any of severalcommercial and well known devices, such as Decagon EC-5 (Decagon DevicesCorp., Pullman, Wash.) or Irrometer Watermark 200 SS (Irrometer Co.,Riverside, Calif.).

In operation of the system, surface water is applied in abundance inflood irrigation, in amounts greater than what the existing vegetationcan use. The water presence/depth measurement device 52 providesinformation on depth of water in the field, primarily for use of thefarmer. Alternatively, water is applied by spraying, or microirrigation. As water is absorbed down into the soil, it will passthrough the root zones. The subsurface moisture sensors 294, 296 and 298can be used to monitor takeup of water by the plants, providing feedbackuseful to the farmer in fine tuning amounts of water to be applied indifferent fields. These moisture sensors also indicate dryness of thesoil between flood applications, and the need for watering.

Below the root zone of the plants, the sensor 300 detects excess waterbeyond that taken up by the plants, migrating down toward the watertable. This indicates groundwater recharge. The amount of the rechargeor replenishment taking place over time can be roughly calculated basedon a number of factors, including the type of soil and the character ofsubsurface strata. As mentioned above, this same subsurface measurementmethod can be used at groundwater replenishment basins, on farms orelsewhere.

Estimated groundwater replenishment can be balanced against a farm's (orgroup of farms') water use, for credits against restrictions on use orother purposes.

The above described preferred embodiments are intended to illustrate theprinciples of the invention, but not to limit its scope. Otherembodiments and variations to these preferred embodiments will beapparent to those skilled in the art and may be made without departingfrom the spirit and scope of the invention as defined in the followingclaims.

We claim:
 1. A method for monitoring replenishment of groundwater on anirrigated farm or group of farms or another land area subject togroundwater depletion, comprising: installing moisture sensor devicesbelow grade at a plurality of locations on a farm or group of farms,with sensor probes at a series of subsurface depths including below rootlevels of any vegetation, the moisture sensor devices having wirelessdata transmission capability for transmission of moisture content datasignals over a distance, and at a monitoring location remote from thefarm or land area, monitoring soil moisture content at a series ofdepths and at plural locations on the farm or farms or other land areausing data as transmitted by the moisture sensor devices, so thatreplenishment of groundwater at the farm or farms can be determined bymoistening of subsurface soils, including below roots, indicatingmigration of water down to a water table, thereby providing informationuseful in balancing water use, including groundwater use, against anestimated replenishment of groundwater by water seepage throughsubsurface soil down to the water table.
 2. The method of claim 1, on afarm or farms which utilize surface irrigation water delivered in apipe, ditch or canal, and wherein depth of water in the pipe, ditch orcanal is monitored by wireless distance measuring devices positionedabove a water surface in the pipe, ditch or canal, utilizing ultrasonictransmission or radar, each of the distance measuring devices havingwireless data transmission capability for transmitting water level dataover a distance such as to be received at the monitoring location, sothat delivery of irrigation water on the farm or farms and status ofwater in the pipe, ditch or canal can be monitored, along with estimatedgroundwater replenishment at the farm or farms.
 3. The method of claim2, wherein volumetric flow of water through the pipe, ditch or canal isalso monitored by flow measurement equipment having wireless datatransmission capability over a distance such as to be received at themonitoring location, whereby irrigation water use at the farm or farmscan be compared against said estimated replenishment of groundwater. 4.The method of claim 2, wherein the farm or farms include at least onegroundwater replenishment basin, wherein a portion of the deliveredirrigation water at the farm or farms can be diverted into thegroundwater replenishment basin, at least one of said moisture sensordevices being positioned below ground at the groundwater replenishmentbasin.
 5. The method of claim 1, wherein the farm or farms or other landarea include at least one groundwater replenishment basin, wherein aportion of the delivered irrigation water at the farm or farms can bediverted into the groundwater replenishment basin, at least one of saidmoisture sensor devices being positioned below ground at the groundwaterreplenishment basin.
 6. The method of claim 1, wherein transmissions ofmoisture content data to the monitoring location are indirect, firstreceived at one or more wireless hubs, then relayed via a network to themonitoring location.
 7. The method of claim 2, wherein the water leveldata are tied to geographic location of each distance measuring device.